1. Field of the Invention
The present invention relates to a method and apparatus for nonplanar micro-fabrication and processing on flexible, filamentary structures. More particularly, the present invention relates to a method and apparatus for physical vapor deposition of materials on long, flexible filamentary substrates by holding each end of a deposition area on the filament to maintain the filament in a substantially straight configuration and to physically mask the filament outside the deposition area, and by simultaneously rotating the filament about one or two axes to uniformly deposit the material on the filament.
2. Prior Art
Lithographic techniques have been utilized for some time in the manufacture especially of integrated circuit boards and semiconductor devices and related products. The products manufactured have typically included planar surfaces to which the lithographic techniques were applied. Such techniques have proven extremely effective in the precise manufacturing and formation of very small details in the product. However, attempts to apply such techniques to other than planar surfaces have proven difficult, if not unachievable, until recently. With recent developments in nonplanar lithography, the fabrication of microstructures, including both three-dimensional mechanical parts and three-dimensional electrical components, has become more readily achievable. U.S. Pat. No. 5,106,455, issued Apr. 21, 1992, to Jacobsen et al. discloses a method and apparatus for fabricating microstructures using nonplanar, exposure beam lithography. Using this method and apparatus, very fine, precise and detailed physical structures can be formed on very small three-dimensional objects such as, for example, cylinders. U.S. Pat. No. 5,269,882, issued Dec. 14, 1993, to Jacobsen discloses a method and apparatus for fabricating thin-film semiconductor devices using nonplanar, exposure beam lithography. In particular, a variety of semiconductor devices can be formed on three-dimensional substrates, again such as cylinders. The methods and apparatus disclosed in the above two patents provide for fabrication of individual microstructures or thin-film semiconductor devices in a type of batch processing approach. U.S. Pat. No. 5,273,622, issued Dec. 29, 1993, to Jacobsen discloses a continuous processing approach for fabricating microstructures and thin-film semiconductor devices. Such microstructures are finding use in a variety of areas including medical devices, robotics, navigation equipment, motors and similar equipment. U.S. Pat. No. 5,481,184, issued Jan. 2, 1996, to Jacobsen discloses a system for movement actuators and sensors on very small mechanical parts, such as fibers and filaments. U.S. Pat. No. 5,270,485, issued Dec. 14, 1993, to Jacobsen discloses a three-dimensional circuit structure with electrical components formed on the surfaces of elongated cylindrical substrates. With the development of these very small (termed "micro") mechanical devices and electrical elements, the ability to fabricate detailed features of such devices and elements in an efficient and precise way is greatly desired.
The problems faced in fabricating detailed features of these microstructures include the extremely small size of the features and structures and also the nonplanar nature of the structures. In addition, the structures may be relatively long and flexible.